Explaining Systematic Bias in Self-Reported Measures: Factors that Affect the Under- and Over-Reporting of Self-Reported Arrests

The self-report method of collecting data on delinquency, crime, and arrests continues to be one of the most popular techniques of examining the causes of such behavior and assessing the bias in the responses to it. However, the problem of systematic bias in reporting such data continues to cloud its use. Self-report data from a longitudinal study of youth at high risk for serious delinquent behavior are compared with data from official police records to examine systematic bias in both the under-reporting and over-reporting of self-reported arrests. Although under-reporting and over-reporting occur in nearly equal proportions in our data, we find that these two phenomena operate quite differently. Further, we show that systematic bias of self-reported arrests is largely a function of the number of official arrests, and that the effect is non-linear. We offer explanations for these findings, and discuss their implications for the future use of self-report methods.